Method and apparatus for brazed engine components

Abstract

A method and apparatus for brazed engine components include machining an engine component, such as using a casting process, to form an aperture in the component. A brazing material is provided in the aperture to close the aperture and seal an interior of the engine component. A shaped cooling hole is machined in the brazing material to cool the brazing material during engine operation.

What is claimed is: 
     
         1 . A method of converting a hole to a cooling passage in component of a turbine engine, the method comprising:
 filling the hole with a filling material; and   forming a shaped cooling passage in the filling material, wherein the shaped cooling passage is smaller in cross-section than the hole.   
     
     
         2 . The method of  claim 1  further comprising adaptively machining the filling material wherein adaptively machining the filling material includes identifying or shaping the filling material and forming the shaped cooling passage in the filling material based upon such identification or shaping. 
     
     
         3 . The method of  claim 2  wherein adaptively machining the filling material further includes identifying a three-dimensional shape of the filling material. 
     
     
         4 . The method of  claim 3  wherein identifying the shape of the filling material further comprises sensing a height of the filling material extending from the hole. 
     
     
         5 . The method of  claim 3  wherein identifying the shape of the filling material includes a vision system. 
     
     
         6 . The method of  claim 2  wherein adaptively machining the filing material further includes shaping a portion of the filling material to a predetermined height extending from a surface the hole is located in. 
     
     
         7 . The method of  claim 6  wherein machining the filling material to a predetermined height includes machining a flat surface on the filling material. 
     
     
         8 . The method of  claim 2  wherein adaptively machining the filling material further includes optimizing machining parameters to be adaptive to varying filling material heights by accommodating variable filling material heights against a nominal height of the filling material. 
     
     
         9 . The method of  claim 1  wherein forming a shaped cooling passage in the filling material further includes machining the shaped cooling passage to have a diverging portion relative to an airflow path through the shaped cooling passage. 
     
     
         10 . The method of  claim 1  wherein forming a shaped cooling passage in the filling material further includes machining the shaped cooling passage to have a converging portion relative to an airflow path through the shaped cooling passage. 
     
     
         11 . The method of  claim 1  wherein at least a portion of the shaped cooling passage has a variable cross-section relative to an airflow path through the shaped cooling passage. 
     
     
         12 . The method of  claim 1  wherein the hole is a casting hole. 
     
     
         13 . The method of  claim 1  wherein the filling material is a brazing material and forms a braze at the hole. 
     
     
         14 . The method of  claim 1  wherein the hole is an oxidized area of an engine component requiring filling. 
     
     
         15 . A method of brazing an airfoil cast core including a casting hole, remnant of a casting process, the method comprising:
 filling the casting hole with a brazing material having a lower melting point that the cast core; and   forming a shaped cooling passage into the brazing material, with the shaped cooling passage having an inlet and an outlet;   wherein the shaped cooling passage includes a variable cross-sectional area along at least a portion of the passage between the inlet and the outlet.   
     
     
         16 . The method of  claim 15  further comprising adaptively machining the braze wherein adaptively machining the braze further includes identifying a three-dimensional shape of the braze. 
     
     
         17 . The method of  claim 16  wherein adaptively machining the braze further includes machining a portion of the braze to a predetermined height extending from a surface the casting hole is located in. 
     
     
         18 . The method of  claim 5  wherein the variable cross-sectional area includes a diverging portion. 
     
     
         19 . A component for a turbine engine comprising:
 a wall separating an interior from an exterior;   a cooling circuit located within the component and having a cooling passage extending at least partially through the interior;   a hole formed in the wall;   a volume of filling material provided in the hole having a melting point lower than that of the wall; and   a shaped cooling passage formed in the filling material having a variable cross-sectional area along at least a portion of the shaped cooling passage.   
     
     
         20 . The component of  claim 19  wherein the variable cross-sectional area defines a converging portion relative to an airflow direction through the shaped cooling passage. 
     
     
         21 . The component of  claim 20  wherein the variable cross-sectional area defines a diverging portion relative to an airflow direction through the shaped cooling passage. 
     
     
         22 . The component of  claim 19  wherein the wall further includes a tip of an airfoil. 
     
     
         23 . The component of  claim 22  wherein the hole is a casting hole. 
     
     
         24 . The component of  claim 23  wherein the filling material is a brazing material.